The PAX index was developed by Rick Ruth and reflects study of results from well over 500 nationwide Solo events. The below information is sourced from the official PAX webpage.
| Category | Class | Multiplier (2023) | Multiplier (2022) | Difference |
|---|---|---|---|---|
| Street | A Street | 0.823 | 0.821 | 0.002 |
| Street | B Street | 0.818 | 0.818 | 0 |
| Street | C Street | 0.811 | 0.810 | 0.001 |
| Street | D Street | 0.808 | 0.807 | 0.001 |
| Street | E Street | 0.792 | 0.792 | 0 |
| Street | F Street | 0.813 | 0.814 | -0.001 |
| Street | G Street | 0.794 | 0.794 | 0 |
| Street | H Street | 0.786 | 0.786 | 0 |
| Street | Super Street | 0.833 | 0.830 | 0.003 |
| Street R | Super Street R | 0.846 | 0.846 | 0 |
| Solo Spec | Solo Spec Coupe | 0.807 | 0.809 | -0.002 |
| Street Touring | Street Touring Hatch | 0.812 | 0.812 | 0 |
| Street Touring | Street Touring Roadster | 0.831 | 0.828 | 0.003 |
| Street Touring | Street Touring Sport | 0.814 | 0.813 | 0.001 |
| Street Touring | Street Touring Ultra | 0.830 | 0.829 | 0.001 |
| Street Touring | Street Touring Xtreme | 0.817 | 0.817 | 0 |
| Street Touring | Super Street Touring | 0.837 | 0.841 | -0.004 |
| Street Prepared | C Street Prepared | 0.860 | 0.864 | -0.004 |
| Street Prepared | D Street Prepared | 0.844 | 0.844 | 0 |
| Street Prepared | E Street Prepared | 0.840 | 0.840 | 0 |
| Street Prepared | F Street Prepared | 0.828 | 0.824 | 0.004 |
| Street Prepared | Super Street Prepared | 0.855 | 0.853 | 0.002 |
| Street Modified | Street Modified | 0.868 | 0.868 | 0 |
| Street Modified | Street Modified FWD | 0.847 | 0.845 | 0.002 |
| Street Modified | Super Street Modified | 0.879 | 0.883 | -0.004 |
| Prepared | C Prepared | 0.858 | 0.854 | 0.004 |
| Prepared | D Prepared | 0.865 | 0.865 | 0 |
| Prepared | E Prepared | 0.856 | 0.850 | 0.006 |
| Prepared | F Prepared | 0.877 | 0.874 | 0.003 |
| Prepared | X Prepared | 0.884 | 0.885 | -0.001 |
| Modified | A Modified | 1.000 | 1.000 | 0 |
| Modified | B Modified | 0.980 | 0.988 | -0.008 |
| Modified | C Modified | 0.896 | 0.895 | 0.001 |
| Modified | D Modified | 0.898 | 0.898 | 0 |
| Modified | E Modified | 0.911 | 0.909 | 0.002 |
| Modified | F Modified | 0.914 | 0.908 | 0.006 |
| Modified | Kart Modified | 0.933 | 0.931 | 0.002 |
| Formula | Formula SAE | 0.981 | 0.989 | -0.008 |
| CAM | Classic American Muscle Contempory | 0.827 | 0.819 | 0.008 |
| CAM | Classic American Muscle Sport | 0.845 | 0.838 | 0.007 |
| CAM | Classic American Muscle Traditional | 0.819 | 0.816 | 0.003 |
| Xtreme Street | Xtreme Street S | 0.851 | 0 | |
| Xtreme Street | Xtreme Street A | 0.842 | 0 | |
| Xtreme Street | Xtreme Street B | 0.848 | 0 | |
| Electric | Electric Vehicle | 0.832 | 0 | |
| Heritage Classic | Heritage Classic Race Tire | 0.815 | 0.815 | 0 |
| Heritage Classic | Heritage Classic Street Tire | 0.793 | 0.793 | 0 |
| Category | Class | Multiplier (2023) | Multiplier (2022) | Difference |
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